1900.] A. Alcock — Garcinological Fauna of India. 343 



ii. Tympana ill defined : external maxilli- 

 peds of moderate size, the merus larger 

 than the ischium : the chelipeds of the 

 female, though not so stout as those of 



the male, are stouter than the legs Tympanomerus. 



2. The antennules fold obliquely or quite trans- 

 versely : no "tympana" are present on any 

 of the joints of the legs (Macrophthalminae) : — 

 i. Merus of the external maxillipeds 

 smaller than the ischium, the flagellum 

 coarse and articulating at the antero- 

 external angle of the merus : front 



deflexed : eyestalks often very long Macrophthalmus. 



ii. Merus of the external maxillipeds as 

 large as or larger than the ischium, at 

 least the two terminal joints of the 

 flagellum ore slender : eyestalks not 

 particularly long : — 



a. Front declivous : carapace slightly 

 convex : the flagellum of the exter- 

 nal maxillipeds articulates at the 

 antero-external angle of the merus : 

 (the chelipeds of the female, as in 

 all Macrophthalminae, are shorter 



and slenderer than the legs) Clistostoma. 



b. Front square-cut, not in the least 

 deflexed ; carapace quite flat dor- 

 sally : the flagellum of the external 

 maxillipeds articulates near, but 

 not at, the antero-external angle of 

 the merus : eyes not terminal on the 



eyestalks , Tylodiplax. 



Subfamily Ocypodinjj, Dana. 



Ocypoda, Fabr. 



Ocypoda, Fabricius, Ent. Syst. Suppl. p. 347 : Desmarest, Consid. Gen. Crust. 

 p. 119, and Diet. Sci. Nat. XXVI II. p. 239 : De Haan, Faun. Japon. Crust, p. 29 : 

 Milne Edwards, Hist. Nat. Crust. II. 41, and Ann. Sci. Nat., Zool., (3) XVIII. 1852 

 p. 141: Dana, U. S. Expl. Exp. Crust, pt. I. p. 324: Kingsley, Proc. Ac. Nat. Sci. 

 Philad. 1880, p. 179 : Miers, Ann. Mag. Nat. Hist. (5) X. 1882, p. 376, and Challenger 

 Brachyura, p. 237: Ortmann, Zool. Jahrb., Syst., X. 1897-98, p. 359 (Revision der 

 Gattung Ocypoda). 



Carapace deep, square or subquadrilateral, broader (but not much 

 broader) than long, moderately convex, strongly declivous anteriorly, 

 its dorsal surface closely granular with the regions indistinctly and 

 incompletely defined. Front a narrow deflexed lobe, from a seventh to 

 an eighth the greatest breadth of the carapace. 

 J. n. 45 



